| ; RUN: opt -S -functionattrs %s | FileCheck %s |
| declare nonnull i8* @ret_nonnull() |
| |
| ; Return a pointer trivially nonnull (call return attribute) |
| define i8* @test1() { |
| ; CHECK: define nonnull i8* @test1 |
| %ret = call i8* @ret_nonnull() |
| ret i8* %ret |
| } |
| |
| ; Return a pointer trivially nonnull (argument attribute) |
| define i8* @test2(i8* nonnull %p) { |
| ; CHECK: define nonnull i8* @test2 |
| ret i8* %p |
| } |
| |
| ; Given an SCC where one of the functions can not be marked nonnull, |
| ; can we still mark the other one which is trivially nonnull |
| define i8* @scc_binder() { |
| ; CHECK: define i8* @scc_binder |
| call i8* @test3() |
| ret i8* null |
| } |
| |
| define i8* @test3() { |
| ; CHECK: define nonnull i8* @test3 |
| call i8* @scc_binder() |
| %ret = call i8* @ret_nonnull() |
| ret i8* %ret |
| } |
| |
| ; Given a mutual recursive set of functions, we can mark them |
| ; nonnull if neither can ever return null. (In this case, they |
| ; just never return period.) |
| define i8* @test4_helper() { |
| ; CHECK: define noalias nonnull i8* @test4_helper |
| %ret = call i8* @test4() |
| ret i8* %ret |
| } |
| |
| define i8* @test4() { |
| ; CHECK: define noalias nonnull i8* @test4 |
| %ret = call i8* @test4_helper() |
| ret i8* %ret |
| } |
| |
| ; Given a mutual recursive set of functions which *can* return null |
| ; make sure we haven't marked them as nonnull. |
| define i8* @test5_helper() { |
| ; CHECK: define noalias i8* @test5_helper |
| %ret = call i8* @test5() |
| ret i8* null |
| } |
| |
| define i8* @test5() { |
| ; CHECK: define noalias i8* @test5 |
| %ret = call i8* @test5_helper() |
| ret i8* %ret |
| } |
| |
| ; Local analysis, but going through a self recursive phi |
| define i8* @test6() { |
| entry: |
| ; CHECK: define nonnull i8* @test6 |
| %ret = call i8* @ret_nonnull() |
| br label %loop |
| loop: |
| %phi = phi i8* [%ret, %entry], [%phi, %loop] |
| br i1 undef, label %loop, label %exit |
| exit: |
| ret i8* %phi |
| } |
| |
| |